Method of making molded articles



March 27, 1934. B. BEDFORD 1,952,528

METHOD OF MAKING MOLDED ARTICLES Filed Feb. 27, 1930 2 Sheets-Sheet l .IIIIH v 4 gwmzntoz .BeucE Basra/e0 March 27, 1934. B, BEDFQRD METHOD OF MAKING MOLDED ARTICLES 2 Sheets-Sheet 2 Filed Feb- 27, 1930 7 BRUCE Beorona Patented Mar. 27, 1934 l a V I y urrs. srrss are 7 I Q I a I v i I 1,952,528 4 METHGD Gill MAKING MOLDED ARTICLES 7 Bruce Bedford, Trenton, N. J. Application February 27, 1930, Serial No. 431,901

' The invention relates to a method of'manufacand around the slab so as to completely cover allturing a molded article possessing high insulatportions of the central cork core, this rubber being properties and comprising an integral impering in an amount in excess of that which will be vious-casing of hard rubber otherwise known as present in the completed article.- v -5 ebonite, the interior being filled with-insulating The upper section 11 of the mold is placed in material, preferably of a porous spongy nature, the position illustrated in Fig. 5, and pressure is such as cork, from which all the air has been then applied, producing compression of the cork removed. Such articles may be constructed in core to the reduced size indicated in Fig. 6. All 7 different forms, according to the uses to which a or a substantial portion of the air previously in- 10--they are to be put, and have been successfully eluded within the cork core escapes through the utilized as lids for ice cream cabinets, for insusplit 14 in the mold, to the outer atmosphere. lating door frames, and in other relations where The rubber, during this stage of the process, flows high insulating properties are necessary or deonly to a sufilcient degree to permit the escape sirable. of air. I 15 i According to the preferred method of manu- Heat is now applied suificient to cause the rubfacture, a coating of rubber is molded about a bar to become soft, and to flow freely. This-recore of cork or similar porous spongy material, sults in the excess of rubber flowing through the such coating being continuous and integral, and split 14 in the mold to the overflow space 15, be-

extending over the entire surface of the interior ing forced out partly by the expansion oi the Q 'slab of cork. The coated slab within the mold is compressed cork core 12. The cork returns ap then subjected to heat and pressure, the heat proximately to its original size, due to the resilbeing sufficient to render the rubber fluent, and iency or spring of the cork, which is sufficient to the pressure being sufiicient to force the air out force the excess of flowing rubber out of the form of the cork. Subsequently expansion of the cork and into the overflows. When this operation is 25 is allowed to take place while the cork is entirely completed, the temperature is again raised, and

covered with the impervious rubber coating, the the curing process is started. result being that vacuum spaces exist within the When the curing is completed, the cork core body of the cork in place of the air, thus producentirely surrounded by a permanent impering an article having improved insulating propvious integral coating of hard rubber, and vacg 'j' ti uum spaces indicated at 16 take the place of the The above is a brief description of the improved previously within the cork slab. Preferably article and a preferred method of manufacture, rim i7 is i'ormed integral with the rubber coatbut the invention will be more readily understood ing or casing 13. by reference to the accompanying drawings and By the process above described, it is possible ggiinore detailed description which will follow hereto produce an article which possesses higher ihafter. insulating properties than those commonly in use.

In the drawings, The cork core is entirely surrounded by the im- Fig. 1 is a transverse sectional view of an ice pervious outer coating, so that it is impossible for cream cabinet lid formed in accordance with my air to enter and fill the vacuum spaces. The

40 invention; process simple and results in marked savings Fig. 2 is a top plan view of the same; the cost of manufacture, as well as producing Fig. 3 is a sectional view of a sliding door frame on improved article. constructed in accordance with my invention; The molded article of manufacture may be em- Fig. 4 is an elevation of the same; and ployed for various uses, several of which are illus- 3 Figs. 5, 6 and 7 are diagrammatic sectional trated in Figs. 1 to 4/ Fig. 1 shows an ice cream views showing a mold within which the improved cabinet lid comprising in outer rubber casing 18, article is formed, the three figures illustrating which entirely covers a cork core 19 having vacsuccessive steps in the manufacture of the article. uum spaces 20 within the same. A flange 21 is Referring first to Figs. 5, 6 and '7, the reference formed integral with the rubber casing 18, and

numeral 10 denotes the bottom portion of a mold, provides a rest for the lid. A suitable handle 22, Q

and the numeral 11 a separate upper portion of which may be of hard rubber or other desired the same mold, used for the production of my material, is attached to the lid.

improved rubber coated insulating article. A cork In Figs. 3 and 4, the invention is shown as apslab 12, is first placed within the lower section 10 plied to a sliding door frame which surrounds a of the mold, with the rubber in plastic condition, central portion 23. The frame possesses insulat- 10* ing properties, and comprises a casing 24, preferably of hard rubber, which completely surrounds the insulating core 25, of cork or light spongy material, having vacuum spaces 26 therewithin, or other insulating materials. One or more flanges 27 may be formed integrally with the casing 24 to form a backing for the glass or other material used to close the space 23.

Obviously the invention is capable of other modifications, those described being merely illustrative of the broad utility of the device.

The idea of molding rubber entirely around an insulating core, preferably of cork or like spongy material, in one integral piece, thereby eliminating any possibility of air or moisture coming in contact with the core, is believed to be one of the important features of the present invention.

What is claimed is:

1. A method of making a molded article of manufacture having an imperforate air and moisture impervious hard rubber casing and a cork spongy porous core having vacuum spaces therewithin, which comprises completely surrounding a cork core in a mold with a plastic hard rubber composition, applying pressure sufficient to compress the cork core and to remove the air therefrom, heating the rubber casing sufficiently to render the same fluid, and at the same time permitting the cork to expand, whereby a vacuum occupies the spaces previously occupied by air, then curing the rubber casing and allowing the same to harden about said expanded core.

2. A method of forming an insulating block having an imperforate air and moisture impervious outer casing and a spongy core having vacuum spaces therewithin, which comprises completely surrounding a spongy core within a mold with plastic casing impervious to air, applying pressure sufficient to compress the core and to remove the air therefrom, heating the casing sufficientiy to render the same fluid, and at the same time permitting the core to expand, whereby a vacuum occupies the spaces previously occupied by air, then allowing the casing to harden about the said expanded core.

BRUCE BEDFORD. 

